The Los Angeles-based company’s interim chief financial officer resigned last week, and its chief operating officer left last month. Meanwhile, its cash supply has dwindled, an employee familiar with the firm’s finances said. But the company is likely to receive more funding soon, its biggest investor said.

Founded in 2013, Cargomatic is one of a host of startups offering to match shippers with trucking companies via apps and websites. These “Uber for trucking” businesses aim to provide a faster, cheaper alternative to the brokers who dominate the $57 billion U.S. transportation management market, where many freight loads are still booked by phone.

Research firm Armstrong & Associates estimated in July there were 27 companies offering digital freight-matching services. They have raised more than $180 million from venture-capital firms since 2011, with over one-third of that funding coming this year alone, Armstrong said.

Cargomatic’s niche is arranging truck transportation around major U.S. ports, where thousands of independent truckers and small fleets carry freight from the docks to nearby warehouses and rail yards. The company raised $8 million in a January 2015 funding round led by venture-capital firm Canaan Partners.

But Cargomatic has struggled this year, laying off around a third of its staff in March, as the number of containers passing through U.S. ports has stagnated and the startup sought to automate more services, said Hrach Simonian, a general partner at Canaan, who sits on Cargomatic’s board.

Startups typically aim to have cash to fund at least six to nine months, analysts say. They risk running out of funds to meet payroll and other obligations if their cushion gets too low.

Cargomatic has enough cash to cover about two months of operating costs, the person familiar with their financial situation said.

Mr. Simonian said the company isn’t facing a cash crunch and that Canaan is planning to invest more money in it. “The fact that there’s two months of cash left is irrelevant,” Mr. Simonian said. “They have [an] indefinite runway…There will absolutely be a new cash infusion in the company in short order.”

The closely held Cargomatic hasn’t disclosed financial data.

In May, Cargomatic co-founder Jonathan Kessler stepped down as chief executive amid pressure from Canaan. He now serves as Cargomatic’s chief product officer. The company doesn’t currently have a chief executive.

Interim Chief Financial Officer Seth Klein resigned earlier this month, and Chief Operating Officer Sean Whiteley left in July, Mr. Simonian said. Both moves as well as Cargomatic’s cash position were originally reported by DC Velocity, a trade publication.

“I think they found out that there were other people being brought in and they saw the writing on the wall,” Mr. Simonian said. “Then they left.”

Mr. Klein and Mr. Whiteley couldn’t be reached for comment.

Richard Gerstein, who in June was named chairman of Cargomatic’s board of directors, said the company needed to “recalibrate” its management. “There’s a perception in Silicon Valley that you can just start with a blank piece of paper and you don’t need to know the rules. That might work in some industries, but not in freight transportation,” he said. “To scale this company, we need people who have knowledge of the traditional technology in manufacturing and distribution.”

Cargomatic’s problems come as freight-technology startups are drawing growing interest from investors. Transfix, a New York-based mobile app developer that connects companies looking to ship goods with truck drivers, raised $22 million in Series B funding in July, one of the largest investment rounds for a company of this type.

Some technology-focused freight companies have partnered with traditional logistics firms to grow. In June, DB Schenker, one of the world’s largest logistics companies, agreed to use Austin, Tex.-based uShip Inc.’s digital freight-booking platform in Europe.